Blacks and Hispanics at higher risk for precancerous colorectal polyps

(Press-News.org) New York, NY (May 3, 2012) — Blacks and Hispanics have a significantly higher risk of developing precancerous colorectal polyps compared with whites, according to a study by researchers at NewYork – Presbyterian Hospital/Columbia University Medical Center. The findings appeared in the online edition of Alimentary Pharmacology and Therapeutics.

"Our data suggest that we need to redouble our efforts to increase colon cancer screening in areas with large numbers of racial and ethnic minorities," said lead author Benjamin Lebwohl, MD, MS, assistant professor of clinical medicine and epidemiology at NewYork – Presbyterian Hospital/Columbia University Medical Center and Columbia University's Mailman School of Public Health.

The study also found that blacks and Hispanics have a higher risk of developing polyps in the upper portion of the colon, compared with whites. "These lesions would have been missed had these patients undergone sigmoidoscopy, which examines only the lower half of the colon," said Dr. Lebwohl. "Therefore, colonoscopy, which examines the entire colon, may be preferable to sigmoidoscopy as a screening test for blacks and Hispanics."

Colorectal cancer caused an estimated 51,370 deaths in 2010 – the last year for which data are available. This type of cancer is largely preventable if caught early, in the form of precancerous polyps, or adenomas. Such polyps are effectively treated with removal during colonoscopy.

The researchers looked at rates of advanced adenomas — polyps 10 mm or larger that exhibited aggressive features under microscopic examination. "These are the kinds of polyps that we are most concerned may eventually develop into cancer," said Fay Kastrinos, MD, MPH, assistant professor of clinical medicine at NewYork – Presbyterian Hospital/Columbia University Medical Center and senior author of the study. "We found that blacks and Hispanics were roughly twice as likely to have advanced adenomas, compared with whites, after adjusting for factors such as age and family history."

Previous studies had shown that colorectal cancer incidence and mortality are higher in blacks than in whites, and that blacks are typically younger at the time of diagnosis than are whites. Little was known about the risk of adenomas among Hispanics.

In the current study, the first to compare adenomas in white, blacks, and Hispanics, the investigators analyzed data from 5,075 men and women age 50 or older who underwent first-time colonoscopy at NewYork – Presbyterian Hospital/Columbia University Medical Center from 2006 to 2010. The study population was 70 percent white, 18 percent Hispanic, and 12 percent black, with a mean age of 62. None of the subjects had signs or symptoms of colon cancer at the time of screening. At least one adenoma was detected in 19 percent of whites, 22 percent of Hispanics, and 26 percent of blacks, the researchers reported.

The findings run counter to existing statistics showing that Hispanics have a lower rate of colon cancer compared with whites. "Surprisingly, we found that Hispanics have a slightly higher rate of precancerous polyps," said Dr. Lebwohl. "This adds to other recent evidence that the rate of colorectal cancer among Hispanics may be increasing with acculturation."

Doctors generally advise patients to get an initial screening test at age 50, when overall rates of colon cancer begin to increase.

### The research paper is titled, "Risk of colorectal adenomas and advanced neoplasia in Hispanic, black and white patients undergoing screening colonoscopy." The other co-authors are Kristina Capiak and Alfred. I. Neugut, at NewYork – Presbyterian Hospital/Columbia University Medical Center.

This research was supported by the National Center for Research Resources (KL2 RR024157, BL) and the National Cancer Institute (K07 CA151769-01, FK).

The authors declare no financial or other conflicts of interest.

Columbia University Medical Center provides international leadership in basic, pre-clinical and clinical research, in medical and health sciences education, and in patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Established in 1767, Columbia's College of Physicians and Surgeons was the first institution in the country to grant the M.D. degree and is among the most selective medical schools in the country. Columbia University Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest in the United States.